Latest International GBAS Working Group

Hosted in Brazil

The seventh meeting of the international 

Ground Based Augmentation System 

(GBAS) Working Group (IGWG) was hosted 

from April 9th-11th, 2008 in Rio de Janeiro by 

Brazil’s Departamento de Controle do Espaço 

Aéreo (DECEA). The IGWG continues to 

be valuable to all participants as it provides 

the only international forum on GBAS 

development and implementation which 

includes services providers, regulators, 

industry, users/airlines, and aircraft 

manufacturers. For this latest meeting, 55 

participants came together to support the 

work of the group. Service providers and 

regulators included the U.S. (FAA), Europe (Eurocontrol), Brazil (DECEA), Chile (Dirección 

General de Aeronáutica Civil - DGAC), Japan (Japanese Civil Aviation Bureau - JCAB), 

Korea, Germany (Deutsche Flugsicherung - DFS), Spain (Aeropuertos Españoles y 

Navegación Aérea - AENA), France (Directorate of Air Navigation Services - DSNA), and 

Australia (Civil AviationSafety Authority). Industry included Honeywell, Thales, Lens/MERC, 

IDS, ENRI, KARI, NEC, and Selex-si. Airlines included Japan Airlines, All Nippon Airways, 

TAM Airlines, and GOL Airlines. Airframe manufacturers included Boeing, Airbus, and 

Embraer. The meeting covered national GBAS activity updates, industry updates, technical 

and operational presentations, and working group sessions. 

The national updates and briefings clearly indicate increased focus and progress on the 

implementation of GBAS. All nations present provided an update on their specific national 

activities. It is evident that GBAS is getting more visibility through an increased number of 

early operational activities like those of Australia, Germany and Spain, as well as an increased 

number of development and data collection activities like those of Brazil, Japan, Korea, 

and Italy. In addition to the national updates, Airbus presented GLS certification flight trial 

and interoperability results of the A380 and A320 trials against the Thales station in Toulouse 

and against the Honeywell station in Malaga (included only the A320). Boeing noted their 

customer base for B737NG Cat I GLS option which included Qantas, Delta, TUIfly, Sonair, 

Air Berlin, and Air Vanuatu. Boeing reported that the B787 and the B747-8 will also have 

GLS as standard avionics equipment and added that new B787 orders have exceeded 600 . 

Technical discussions centered on detailed information exchange between all participants 

on their various activities. Discussions covered the ionosphere (noting the range of 

ionospheric environments in the different regions of the world), GBAS siting activities, and 

In this issue:

Latest International GBAS Working 

Group Hosted in Brazil.................1 

FAA and Chilean DGAC Join 

Together on GBAS 

Implementation.............................2 

Partnership Opportunities to 

Expand WAAS/LAAS Equipage...2 

LPV Watch: FAA’s Annual LPV 

Production Goals Increase..........2 

New ICAO Flight Plan Format 

Coming for RNAV Enroute 

Procedures.................................2 

GEAS Phase I Report Published...3 

GNSS in the News.......................4 

GNSS on the Road.......................4 

Did You Know?............................4 

The SATNAV News is produced by the 

Navigation Services (ATO-W) branch of 

the Federal Aviation Administration. This 

newsletter provides information on the Wide 

Area Augmentation System (WAAS) and 

the Local Area Augmentation System 

(LAAS), and initiatives associated with the 

implementation of satellite navigation into 

the National Airspace System (NAS). 

Federal Aviation Administration 

800 Independence Avenue, SW 

Washington, DC 20591 

http://gps.faa.gov

Rio de Janeiro, host city of the

GBAS Working Group meeting.
2

national data collection and evaluation activities (how this 

data can be shared and made available to interested parties 

to support the overall GBAS development and 

implementation activities). Several GBAS architectures 

(Honeywell, Thales, GM Merc-Curtiss Wright Joint Venture, 

and Spectr) were also discussed as several are available 

and in different stages of development. 

In addition to these briefings, four breakout sessions were 

conducted: 

X Data collection, sharing, test case harmonization 

X Operational approval/implementation issues 

X Local business case and implementation incentives 

X GBAS siting, ionosphere, GBAS critical areas 

The break out sessions provided the opportunity for the faceto-face exchange of information, the identification of 

common issues, and the opportunity to develop joint 

solutions. 

Future meetings will be slightly reorganized to expand the 

time allotted for subgroup discussions and concentrated 

exchange of information and for harmonization of efforts as 

these discussions have proven very effective in leading to 

joint solutions. The next IGWG is planned for early 2009 in 

Europe with a location to be determined. 

- Dieter Guenter, FAA ATO-W / GPS TAC

FAA and Chilean DGAC Join

Together on GBAS Implementation

On March 31st, the FAA and Chilean Dirección General de 

Aeronáutica Civil (DGAC) signed a Memorandum of 

Agreement to solidify future collaboration on Ground-Based 

Augmentation System (GBAS) development. 

More information is available by selecting this link to the 

United States embassy - Santiago website. 

 - Mary Ann Davis FAA ATO-W/GPS TAC

Partnership Opportunities to

Expand WAAS/LAAS Equipage

To further increase WAAS and LAAS applications for 

commercial aircraft, the FAA is planning to release a market 

survey for related government-industry partnerships later this 

summer. The initiative will be targeted to expand 

commercial fleet use of GNSS and related operations in 

support of advanced commercial applications. 

This initiative has dual purposes. For commercial users, 

this initiative will help to identify and implement operational 

applications that will provide cost beneficial business cases 

for equipping and using GNSS navigation and system 

solutions. For the FAA, this initiative will further expand 

WAAS and LAAS use in the National Airspace System and 

support early NextGen operational applications. This 

initiative should also result in an increase in the number of 

Supplemental Type Certificates (STC) for WAAS avionics by 

helping to overcome the initial cost burden associated with 

this process. The STC would then be available to the same 

model of aircraft throughout the industry - a significant 

benefit to the user community at large. The market survey is 

expected to be released in late June or early July. 

 - Mary Ann Davis, FAA ATO-W/GPS TAC

LPV Watch: FAA’s Annual LPV

Production Goals Increase

The FAA’s National Flight Procedures Office (NFPO) has 

increased their production goal to 400 LPVs for 2008. For 

the past three years, NFPO has commissioned at least 300 

LPV procedures each fiscal year. Due to better screening 

and coordination, the FAA has increased the success rate 

to the levels 

where they can 

increase their 

annual goals. In 

2009, the goal will 

be 500 LPV or 

Localizer 

Performance (LP) procedures. More information on LP 

procedures is available in the March 2008 SatNav News. 

Due to congressional language, the NFPO has adjusted 

their schedule to publish more LPVs at non-Part 139 

airports in 2008. Readers visiting the NFPO’s procedure 

schedule webpage will see this notice regarding the LPV 

production schedule. Still, the FAA projects there will be 

more LPVs than the 1,230 ILS instrument approaches 

currently published by September of this year. 

 - Martin Heller, FAA ATO-W/GPS TAC

A listing of current airports and runways

served by LPVs can be found on our

website. To access this information, go

to http://gps.faa.gov and select the GPS/ WAAS Approaches button

from bottom of the front page.

New ICAO Flight Plan Format Coming

for RNAV Enroute Procedures

There is a change, effective June 5th, in the manner in which 

pilots have to file flight plans if they plan on filing RNAV 

(GPS) instrument procedures for their navigation. Pilots 

have to submit the ICAO (International Civil Aviation 
3

Organization), vice the FAA flight plan 

form, in order to get the flight plan 

accepted due to recent changes to the 

air traffic control software. While this is 

not specifically a SATNAV issue, it does 

affect SATNAV users, so we wanted to 

provide our subscribers with this 

information and provide a reference for 

more information. More information can be found in the 

FAA Air Traffic Bulletin issued on March 8, 2008.

 - Martin Heller, FAA ATO-W / GPS TAC

GEAS Phase I Report Published

The GNSS Evolutionary Architecture Study (GEAS) was 

formed to define and evaluate Global Navigation 

Satellite System (GNSS) based architectures 

for providing robust localizer performance with 

vertical guidance (LPV) service worldwide circa 

2020-2030. Specifically, GEAS is focused on 

effective use of the new L5 civil protected frequency. 

A constellation of L5-capable GPS satellites is 

envisioned to be operational in about 2018. 

Earlier this year, the panel published their Phase I report. 

Phase I focused on understanding and bounding the complex 

relationships between satellites, ground processing networks 

and user avionics in monitoring and timely detection of GPS 

signal faults. GEAS Phase I produced three options, each 

which emphasize varying degrees of ground infrastructure to 

avionics responsibility for fault monitoring. 

X GNSS Integrity Channel (GIC) - The GIC provides user 

receivers with GPS status information via geostationary 

satellites (similar to WAAS). The GIC monitor network 

monitors the status of GPS L1 and L5 signals worldwide 

providing fault detection information satisfying avionic time to 

alert requirements (~6 seconds). 

X Relative Receiver Autonomous Integrity Monitoring

(RRAIM) - RRAIM places fault detection equally between a 

monitoring network and the user receiver. The user receiver 

detects differences in the GPS satellite signal carrier phase 

measurements over time. The Monitor network continues to 

monitor for GPS satellite fault conditions and provides this 

information to the user receivers. As the user receiver is able 

to actively participate in fault monitoring, the GPS 

fault information can be forwarded at a lower rate, 

allowing the receiver to ‘coast’ between 

messages on the order of 30 to 300 seconds. 

X Absolute Receiver Autonomous Integrity Monitoring

(ARAIM) - ARAIM places the largest integrity burden on the 

user receiver. The user receiver will detect signal faults using 

redundancy of information from multiple satellites. As such, 

ARAIM requires a very robust satellite constellation (~30 

satellites). A low rate integrity channel is still required, but 

the ARAIM solution allows large intervals (~1 hour) between 

updates. 

The benefits of a dual-frequency (L1 & L5) GPS constellation 

are primarily evidenced when the earth’s ionosphere 

experiences variations in time and in distance (temporal and 

spatial). For North America, nominally the ionosphere is very 

‘well-behaved’ and is well approximated by algorithms 

currently used within the operational Wide Area 

Augmentation System (WAAS). For periods of solar 

activity or in areas of the world where the ionosphere 

is not ‘well-behaved’ (primarily equatorial regions), 

approximations are not as accurate and large 

uncertainty must be accounted for in avionics 

position solutions. This large uncertainty can 

significantly reduce the availability of procedures 

(e.g. LPV). 

With dual-frequency, algorithms in the avionics will be able to 

calculate accurate ionospheric corrections locally, 

significantly improving accuracy even without well-behaved 

ionospheres. However, for aviation (and other applications 

requiring high confidence in the position computed) the 

accuracy of the position estimate must be coupled with highconfidence that all information that is used in the calculation 

of position can be ‘trusted’ (integrity). The three GEAS 

options will all satisfy avionics integrity requirements when 

fielded. The RRAIM and ARAIM solutions will require 

additional study and analysis prior to fielding. 

The GEAS has recently provided a recommendation for the 

pursuit of two options coupled with the Sun’s solar cycle. 

The expected nearest solar cycle peak, 2011, will be 

supported by the WAAS and other regional satellite based 

augmentation systems (SBAS), such as the European 

Geostationary Navigation Overlay Service (EGNOS), GPSaided Geo Augmented Navigation (GAGAN), and the MTSAT 

Satellite-Based Augmentation System (MSAS). The 

following cycle peak will be 11 years later in 

2022. The GPS L1/L5 constellation is 

expected to be complete prior to the start of 

this cycle. The GEAS has recommended that a 

RRAIM implementation be developed, tested and 

implemented prior to the start of this solar cycle. This goal 
4

will support LPV-200 capability with very high availability 

during this solar max period with moderate space, ground 

and avionics development efforts. 

For the following solar max period in 2033, the GEAS will 

investigate an ARAIM solution. Such a solution reduces the 

need for space and ground infrastructure requirements. 

The GEAS Phase I Report can be found in its entirety from a 

link on the main page of the FAA’s GNSS Program website 

at http://gps.faa.gov. 

 - Ed Sigler FAA ATO-W / GPS TAC

GEAS efforts are coordinated and conducted by a panel of experts

from the US Government and academia More information on the origin

of the GEAS and details on the participants can be found in the “GPS

Evolutionary Architecture Study” article in the November 2007 edition

of the SatNav News, p. 10.

GNSS in the News

Below is information on, and embedded links to, a couple of 

articles that may be of interest to our readers. 

X “WAAS – Bigger, Better, Lower, and 

More” by the FAA WAAS Program 

Office. (March/April 2008). FAA 

Aviation News, p. 24. 

X “Innovation: Good, Better, Best – 

Expanding the Wide Area Augmentation 

System” by Timothy R. Schempp. 

(January 1, 2008). GPS World. 

GNSS on the Road

As a part of user outreach, we have included a summary of 

upcoming events where the FAA GNSS Program will be 

participating as an exhibitor. Please stop by and see us if 

you attend. 

Aircraft Owners and Pilots

Association (AOPA) Fly-In

June 7, 2008 

Frederick, MD 

http://www.aopa.org/

15th Biennial International Flight

Inspection Symposium (IFIS)

June 23-27, 2008 

Oklahoma City, OK 

http://www.ifis2008.com 

AirVenture Oshkosh

July 28-August 3, 2008 

Oshkosh, WI 

http://www.airventure.org/

SATNAV News is posted on our website. You may request to be notified by e-mail when new editions are posted by entering your e-mail 

address at http://www.faa.gov/help/subscribe/ and selecting SATNAV News from the list of options. 

If you have any questions on the e-mail registration process, ideas for future articles, or general feedback on the newsletter, please contact 

Mary Ann Davis at maryann.ctr.davis@faa.gov. 

Did you know...?

X ...that WAAS will mark its 5th anniversary this summer. WAAS was officially commissioned into the National 

Airspace System on July 10th, 2003. 

X ...that in September 2008, there will be more U.S. runway ends served by WAAS LPV approach procedures 

than are currently served by ILS. There are also LPVs now available in Canada. 

X ...that the FAA’s WAAS Program Office is helping to fund airport surveys for LPV approach procedures. For 

more information, please contact your local Airport District Office (ADO). 

X ...that over 32,000 WAAS LPV-capable sets of avionics have been purchased to date. 

X ...that WAAS is the first FAA system to enable real operational capabilities and benefits in support of NextGen.